A closure means of the general kind as herein referred usually comprises a single closure disk which is secured in any suitable manner to the bottleneck portion of a bottle for closing its opening, the closure disk being provided in its centre with a single discharge opening allowing the bottled fluid to be discharged whenever a separate closure cap that normally covers this closure disk has been removed from the bottle. Many different designs of such closure means are known including also closure disks which at their central discharge opening are provided with an axially extending spout for directing the fluid during its exit from the bottle and also including different principles for the removable attachment of the closure cap to the bottleneck which is usually done by means of a turn-lock fastener in the form of either a screw-type locking fastener comprising an outer thread on the bottleneck and an inner thread on the closure cap or in the form of a bayonet-type fastener that comprises corresponding male and female working elements also on the bottleneck and the closure cap, respectively.
With all of these known closure means the inherent disadvantage must be faced that when the closure cap has been removed it also will be possible to manipulate the bottled fluid in an eventually unallowable manner by filling into the bottle via the then uncovered discharge opening any arbitrary substance which then will falsify the quality of the bottled fluid. When the closure cap is removed the bottled fluid then of course is also directly subjected to an interchange with the atmosphere which could be detrimental for fluids that necessitate a delicate handling such as certain pharmaceutical compositions or which could even be dangerous in case for example of fluids that generate toxic smokes when exposed to the air.
This invention accordingly deals with the object of providing a closure means of the general kind as above referred which guarantees a more safe-proof botteling of a fluid. In particular, an improved closure means for a bottle would be desirable which when used for a dental apparatus operating with air under pressure for the supply of a fluid to a handpiece will allow the dentist to arrange the bottle on the dental apparatus with any suitable fluid connection through its closure means in a simple and correspondingly safe-proof manner to thereby guarantee that only any special fluid filled into such bottles will be used for any particular dental treatment at the time when the bottle has been arranged on the dental apparatus.